Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comment
. 2012 Dec;125(12):e7; author reply p.e9.
doi: 10.1016/j.amjmed.2012.05.033.

The bias of a 'clean' comparison group

Jason G Lake, Ryan M Seals
Comment

The bias of a 'clean' comparison group

Jason G Lake et al. Am J Med. 2012 Dec.
No abstract available

PubMed Disclaimer

Comment on

Substances

LinkOut - more resources